system validation using Flourescene

[Tuan]

Does anyone have any suggestion as to what I need to do to validation liquid handling system. I want to validate a 96 well head by using flourescene, but I am not sure of what parameters I should be using. I know it's for low volume and that DMSO has to be at a low concentration to be able to detect the flourescene on the ECHO. Please help!

[Jan]

hi,
I'm using fluorescein as a 2e-8 dilution from my stock in PBS as the highest conc. From there I have approx. 2 orders of magnitude to dilute. But you might have to check for your system (Fluorescein and reader) with a calibration curve. It is critical to work at constant (preferably neutral) pH because Fluorescein signal is pH dependant, and to filter all your solutions before you start diluting. Make sure there is no dust in your vessels, because this gives usually high background in the respective wells.
Hope that helped.
Cheers